This episode was part of the crossover event with Private Practice
. At the end of the episode, Derek gets a call from Addison which leads in to the next episode,"Before and After".
Kevin McKidd (Owen Hunt) is now listed as a main cast member and has been added to the opening credits.
Ratings: 15.20 Million Viewers
Trivia: This episode is the first meeting and first kiss of Callie Torres and Arizona Robbins.
Callie's hair has bangs in this episode.
Meredith (opening voiceover): Any first year med. student knows that increased heart rate is a sign of trouble. A racing heart could indicate anything from a panic disorder to something much, much more serious. A heart that flutters, or one that skips a beat, could be a sign of a secret affliction. Or, it could indicate romance which is the biggest trouble of all.
Derek: This is stupid. She's gonna hate this.
Mark: What? Flowers? Girls love this crap.
Derek: It's cliche. I'm a cliche!
Mark: Cliches became cliches for a reason. Because they worked. It's great, isn't it? When you feel so strongly for someone and it's not just about the sex, it is... it's true.
Derek: You should not talk like that.
Lexie: Hey, do you mind if I sit here?
Callie: No. No. (does a shot) I'm just overthinking.
Lexie: You think that he'll tell 'em?
Callie: If he's not an idiot.
Arizona: Dixon's right, you know. You do belong in peds surgery.
Bailey: My own baby almost died last year. Doctors in this hospital, my friends, they all worked to save his life, and I stood outside the room feelin' so useless, so pointless and helpless like I was losing everything in the world. And when he didn't die, see, I knew that I didn't wanna be anywhere near that feeling again. So, I think that makes me pretty unsuitable for pediatric surgery.
Arizona: I'd say that, that makes you uniquely qualified.
Meredith (closing voiceover): It seems we have no control whatsoever over our own hearts. Conditions can change without warning. Romance can make the heart pound, just like panic can. And panic can make it stop cold in your chest. It's no wonder doctors spend so much time trying to keep the heart stable. To keep it slow, steady, regular. To stop the heart from pounding out of your chest. From the dread of something terrible or the anticipation of something else entirely.
Addison Montgomery: Derek takes a phone call at the end of the episode and Addison, his ex-wife, is on the other line. Addison appeared in Seasons 1-3 of Grey's Anatomy as a series regular before leaving for Grey's Anatomy spin-ff Private Practice.